Belt conveying apparatus and image forming apparatus

A belt conveying apparatus for rotating a belt entrained on a plurality of rollers, comprising:

• at least one driving roller among the plurality of rollers, for imparting rotational driving force to the belt;
• at least one driven roller among the plurality of rollers, which does not impart rotational driving force to the belt;
• a driven roller-moving mechanism, which allows two end portions of the driven roller in the axial direction to move independently from each other in a direction perpendicular to a rotational axis of the driven roller and along a line connecting a center contact point of a wound dimension of the belt wound on the driven roller and the rotational axis of the driven roller;
• and
• a positioning- and fixing-mechanism, for positioning and fixing beforehand both ends portions of the belt in the axial direction at respective positions at which sideways movement of the belt is inhibited.

An image-forming apparatus for forming an image on an image receiving material, by heating a photosensitive material upon which an image is recorded and the image receiving material to which the image recorded on the photosensitive material is to be transferred, which the photosensitive material and the image receiving material have been laminated together in presence of a solvent for image formation, thereby transferring the image on the photosensitive material to the image receiving material, the image forming apparatus comprising:

• a heating drum at whose circumferential surface the photosensitive material and the image receiving material which have been laminated together are wound, the circumferential surface of the heating drum being heated by heat from a heating source;
• an endless belt for holding against the heating drum the photosensitive material and the image receiving material which have been laminated together, by moving along a portion of the circumferential surface of the heating drum as a portion of a conveying path, the endless belt being entrained and rotated at a plurality of rollers at a position including both end portions of the portion of the circumferential surface of the heating drum and at a different position from the position of the portion of the conveying path;
• at least one driving roller among the plurality of rollers, for imparting rotational driving force to the belt;
• at least one driven roller among the plurality of rollers, which does not impart rotational driving force to the belt;
• auxiliary rollers attached to the at least one driven roller, which driven roller is a base body thereof, at two positions further outward than two transverse direction end portions of the entrained belt so as to be able to undergo rotation relative to the driven roller, the diameter of each of the auxiliary rollers gradually increasing from an end portion of the auxiliary roller at a transverse direction end portion of the belt when the belt is in a normal position towards the other end portion of the auxiliary roller in the axial direction.

An image-forming apparatus for forming an image on an image receiving material, by heating a photosensitive material upon which an image is recorded and the image receiving material to which the image recorded on the photosensitive material is to be transferred, which the photosensitive material and the image receiving material have been laminated together in the presence of a solvent for image formation, thereby transferring the image on the photosensitive material to the image receiving material, the image forming apparatus comprising:

• a heating drum at whose circumferential surface the photosensitive material and the image receiving material which have been laminated together are wound, the circumferential surface of the heating drum being heated by heat from a heating source;
• an endless belt for holding against the heating drum the photosensitive material and the image receiving material which have been laminated together, by moving along a portion of the circumferential surface of the heating drum as a portion of a conveying path, the endless belt being entrained and rotated at a plurality of rollers at a position including both end portions of the portion of the circumferential surface of the heating drum and at a different position from the position of the portion of the conveying path;
• at least one driving roller among the plurality of rollers, for imparting rotational driving force to the belt;
• at least one driven roller among the plurality of rollers, which does not impart rotational driving force to the belt;
• a driven roller-moving mechanism, which allows two end portions of the driven roller in the axial direction to move independently from each other in a direction perpendicular to a rotational axis of the driven roller and along a line connecting a center contact point of a wound dimension of the belt wound on the driven roller and the rotational axis of the driven roller;
• and
• a positioning- and fixing-mechanism positioning and fixing the two end portions of the driven roller in the axial direction at respective positions at which sideways movement of the belt is inhibited.